While it is hard to believe that many undocumented immigrants had the liberty to leave the country and reenter, it is possible to do so by abusing a tourist visa. The USCIS is saying that if these visits were brief (no details are available on what that means and this is where prosecutorial discretion comes in to play but I would assume that a few days or weeks for the right reasons will quality) and innocent (again no information on what that means but my best guess is that you left the country to tend to a sick family member or to attend a funeral or to complete some essential paperwork or something along those lines) and were undertaken for humanitarian purposes, exceptions will be granted.
Once again, at this time, USCIS has not qualified what it means by humanitarian purpose, but we can conclude that it means that you did not take a beach vacation in Los Cabos, Mexico or went to attend a family wedding. My advice will be consult with a lawyer what to do if you did leave the US.